Deprecate CSS tooltip

[khiga8]

Related: https://github.com/github/accessibility/issues/670

What are you trying to accomplish?

This PR deprecates tooltip. These tooltips are frequently being applied on static elements making them completely inaccessible for groups of our users.

What approach did you choose and why?

We are currently in process of upstreaming a more accessible tooltip to PVC. That work is not complete yet, but I think it's fine to move this to deprecated to discourage usage.

What should reviewers focus on?

If I set this to deprecated, what effect will it have? One painpoint I'm seeing is that these tooltips are frequently being applied to static elements. Is it worth updating examples to not set tooltips on static elements, even though if this is deprecated?

Also, should we explain why we're deprecating this?

Are additional changes needed?

• No, this PR should be ok to ship as is. 🚢

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🦋 Changeset detected

Latest commit: 7dd10eb

The changes in this PR will be included in the next version bump.

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@primer/css	Minor

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[khiga8]

All the examples here set tooltipped on span elements. We strongly want to discourage this. Though I'm moving this to deprecated, would is still be worth updating the examples? I'm not sure how deprecation works.

[jonrohan]

All the examples here set tooltipped on span elements. We strongly want to discourage this. Though I'm moving this to deprecated, would is still be worth updating the examples? I'm not sure how deprecation works.

Yeah I think there's no harm in updating the examples.

In addition to what you've done here, you should add the classes to https://github.com/primer/css/blob/kh-deprecate_tooltip_please/src/deprecations.json with null as the replacement, ie. "tooltipped": null, this will inform the DeprecatedInPrimer erb linter in github/github and stop people from adding more classes.

[khiga8]

@jonrohan Neat linter!! I'm concerned we will need to add linter disable comment to every file given the extensive use of tooltips. I've proposed a PR in erb-lint to allow linter disable by offense (instead of the file-level disable we've hack implemented), but if that does not go through maybe it is worth converting this to a counter.